The team developed a so-called differential pulley block for alpine lightweight synthetic fibre ropes, which will be easy and simple to handle. They calculated and compared different concepts and found a serrated differential roller with three differently sized grooves. The axle of the pulley is suspended from two side plates, which also provide a suspension point for a carabiner. A mechanism presses the rope into the serrations so that it doesn’t just let go. They found a very smart solution for the improvement of pulley blocks for alpine applications.